Machine tool control means



'7 Sheets-Sheet l m'mvron.

Feb. 14, 1961 E. J. SVENSON MACHINE TOOL CONTROL MEANS Original FiledJune 16, 1954 7 Sheets-Sheet 2 Feb. 14, 1961 E. J. SVENSON MACHINE TOOLCONTROL MEANS Original Filed June 16, 1954 '7 Sheets-Sheet 3 INVENTOR.rzasz Jfi'flerwara BY 44% y/ zd Feb. 14, 1961 E. J. SVENSON 4 MACHINETOOL CONTROL MEANS Original Filed June 16, 1954 '7 Sheets-Sheet 4 355Neutral 370 'INVENTOR.

Feb. 14, 1961 E. J. SVENSON 2,971,341

MACHINE TOOL CONTROL MEANS Original Filed June 16, 1954 '7 Sheets-Sheet5 Feed J64 J02 3&5

40 Rapid Rerurn INVENTOR.

jvzasf f 433 502M070 Z? flkmaw Feb. 14, 1961 E. J. SVENSON MACHINE TOOLCONTROL MEANS 7 Sheets-Sheet 6 Original Filed June 16, 1954 illmmm MGMmwm 'ENTOR. Ja /7x76 Feb. 14, 1961 E. J. SVENSON MACHINE TOOL CONTROLMEANS Original Filed June 16, 1954 7' Sheets-Sheet 7 MACHINE TOOLCONTROL MEANS Ernest J. Svenson, Rockford, 'Ill., assignor, by mesneassignments, of one-half to W. F. and John Barnes Company, Rockford,Ill., a corporation of Illinois, and onehalf to Odin Corporation,Rockford, 111., a corporation of Illinois Original application June 16,19-54, Ser. No. 437,067,

now Patent No. 2,921,437, dated Jan. '19, 1960. Divided and thisapplication Mar. '19, 1959, Ser. No. 800,540

8 Claims. (Cl. 6052) The present invention relates to novel metalworking apparatus and more particularly to self-contained machine toolunits which are hydraulically translated on support ways.

This application is a division of my co-pending application Serial No.437,067, filed June 16, 1954, now Patent No. 2,921,437, issued January19, 1960.

One object of the present invention is to provide a novel metal workingapparatus or selfcontained machine tool unit having a hydraulic controlsystem constructed and arranged so that there are a minimum of externalconduits and couplings whereby the apparatus may be operated andmaintained more efficiently.

Still another object of the present invention is to provide an apparatusof the above described type with a hydraulic control system having novelpump means of simplified construction whereby to promote more efficientoperation and ease of maintenance.

A further object of the present invention is to provide novel apparatusof the above described type which includes a hydraulic control systemhaving improved control valve means which may be mounted and operated ina simple and efiicient manner for directing hydraulic fluid fromsuitable pump means to cause reciprocating movement of a machine elementand for causing a slower feeding movement of the machine element.

Other and more detailed objects and advantages of the present inventionwill become apparent from the following description and the accompanyingdrawings wherein:

Fig. 1 is a side elevational view of an apparatus embodying the novelfeatures of the present invention;

Fig. 2 is a right hand and elevational view of the apparatus shown inFig. 1;

Fig. 2a is a cross sectional view taken along the line 2a2a of Fig. 1;

Fig. 3 is a side elevational view of the novel control valve of thepresent invention;

Fig. 4 is a bottom view of the control valve shown in Fig. 3;

Fig. 5 is a rear view of the novel control valve shown in Fig. 3;

Fig. 6 is a somewhat diagrammatic cross sectional view of the novelcontrol valve taken along line 66 in Fig. 7;

Fig. 7 is an end elevational view of the novel control valve; Figs. 8-1lare semi-diagrammatic cross sectional views of the novel control valve,respectively, showing the valve elements in neutral, rapid advance,feed, and rapid return positions;

Fig. 12 is a sectional view of the hydraulic actuator for the slidinghead together with a schematic illustration of fiuid supply circuits forthe actuator;

Fig. 13 is an enlarged fragmentary front elevational view of the slidinghead casting of the apparatus shown in Fig. 1; and

' nited States Patent '0 'ice Fig. 14 is a partially sectionedfragmentary view taken along the line 1414 of Fig. 13.

Referring now more specifically to the drawings wherein like parts aredesignated by the same numerals throughout the various figures, theapparatus shown for the purpose of illustrating the present inventionincludes one or more self-contained machine tool units 40 as shown bestin Figs. 1 and 2.

Mechanical and supporting structures As shown best in Figs. 1 and 2, theself-contained unit 40 of this invention is adapted to be slidablymounted on a base structure 42 and to this end the unit 40 includes ahead casting 44 that is provided with guideways 46 which cooperate withguideways 48 on the base structure. A suitable spindle head 50 ismounted to the face of the head casting by means of screws or the like,not shown, and an electric motor 52 is mounted on the head casting fordriving the spindles through pulleys 51 and 54, a plurality of V-belts56 and a drive shaft 58. The pulley 54 is mounted on one end of thedrive shaft 58 and a gear 60 is fixed on the opposite end of the driveshaft which gear meshes with one or more pickofi? gears 62 mounted onspindle drive shafts 64.

In order to reciprocate the self-contained unit 40 on the base 42, afluid motor is provided. This motor includes a hydraulic cylinder 102secured to the head frame 44, a piston 104 disposed within the cylinderand a piston rod 106 which is fixed to the base as indicated at 108.Preferably, the piston rod is adjustably secured to the base by a pairof nut members.

In order to actuate the fluid motor, a rapid traverse gear pump 110 anda feed pump 112 have been provided, which pumps are mounted or connectedon opposite sides of the head frame 44, as shown best in Fig. 2. Bothpumps 110, 112 are driven from the central shaft 58 through transmissionmeans, not shown, contained in the head frame 44.

The two pumps 110, 112 are used to supply operating fluid to thetranslating cylinder 102 through a control valve 330 which embodiescertain principles of the present invention. As will become apparent,the control valve 330 is constructed so that a complete cycle ofmovement of the head frame or casting 44 includes a rapid forwardtraverse motion, a slower forward feed motion and a rapid return motion.In addition, the valve is provided with a stop or neutral positionbetween the rapid advance and rapid return positions.

The valve 330 includes a body 332 which is provided with transverselyextending passageways 334, 336 and 338, respectively, receiving a mainvalve structure 340, a feed valve stem 342 and a pair of pilot valvestems 344 and 346, Figs. 6-11. A pair of end plates 348 and 350 aresecured to the opposite ends of the body member. The valve body 332 isprovided with an inlet passageway 352 which is adapted to be connectedto the main outlet 156 of the pump structure 110 by conduit orpassageway means 354 described in detail below and schematically shownin Figs. 12 and 8 through 11. Another passageway 356 in the valve bodyis adapted to be connected to the inlet side of the feed pump 112through suitable conduit means 358 and the pre-charging pump section ofthe pump structure 110, which, for the purpose of better illustration,has been schematically shown as separate from the remainder of the pumpstructure 110 in Figs. 12 and 8 through 11 and is generally designatedby the numeral 360. The passageway 356, as shown in Fig. 6, is connectedto the feed valve stem passageway by passageways 357 and 359. The valvebody member 332 is further provided with a passageway 362 which isadapted to be connected to the forward end of the hydraulic cylinder 102through suitable conduit means 364. It should also be noted that thedischarge side of the feed pump 112 is connected to the conduit means364. A passageway 366 is formed in the valve body member, whichpassageway is adapted to be connected to the rear end of the cylinder192 through suitable conduit means 368. A relatively large drainpassageway 370 is also provided in the valve body member, which drainpassageway is connected with the main reservoir in the manner more fullydescribed below.

The various valve stems of the control valve structure are shown in theneutral position in Figs. 6 and 8. In this position, the main valve stem340 is generally centrally located within the passageway or bore 334 andit is releasably retained in this position by means of a spring pressedball detent 372 shown in Fig. 7. The detent is located within anenlarged chamber 374 and is engageable with a groove 376 formed in themain valve stem for retaining the main valve stem in the neutralposition for which the flow of fluid from the rapid traverse pump isthrough the passageway 352 and into the central portion of the mainvalve stem passageway 334 and around a central spool portion 378 of themain valve stem. Then, the fluid passes through a transverse passageway380 formed in the spool portion of the main valve stem and into acentrally located axially extending passageway 382 within the main valvestem. A spring operated orifice or circulating valve 384 is disposedwithin the passageway 382 and is operable to permit fluid to pass out ofthe passageway 382 through a passageway 386 and into the detent chamber374 from where the fluid passes through the drain passageway 370 back tothe reservoir. The pressure relief or circulating valve 384 may be ofany suitable construction and includes adjustable spring means 383 sothat the pressure at which the relief valve opens may be varied asdesired. Preferably, the relief valve should be set to open when thepressure is between 35 and 55 pounds per square inch.

While the valve stems are in the neutral position, fluid under pressurefrom the rapid traverse pump will be maintained in a passageway 390 thatconnects with the central portion of the main valve stem passageway andalso connects with passageways 392 and 394 which are blocked by thepilot valves 344 and 346, respectively. At the same time, fluid underpressure is maintained in the right hand end of the feed valve stempassageway 336 to maintain the feed valve stem in its neutral position,which valve stem is resiliently biased toward the right by means of aspring 396. The fluid under pressure is introduced into the right handend of the valve stem passageway 336 through the passageway 398 whichconnects the central portion of the valve stem passageway 334 with asuitably drilled passageway 400.

While the various valve stems are in the neutral position, the oppositeends of the main valve stem passageway 334 and the left end of the feedvalve passageway 336 are connected with the detent chamber 374 and,thus, the drain passageway 370. More specifically, the left hand end ofthe main valve stem passageway 334 communicates with passageways 402,404 and 4% which connected with the pilot valve passageway 338 inalignment with a reduced diameter portion 408 of the pilot valve stem344. From this portion of the pilot valve passageway, the fluid passesinto a passageway 410 and thence into a passageway 412. The passageway41?. is connected with the detent chamber 374 by means of a passageway414. In the simplified diagrammatic disclosures of Figs. 8 through 11,the passageway 414 is shown as intersecting the pilot valve passagewayin alignment with a reduced diameter portion 416 of the pilot valve stem346 so that the passageway 414 also serves as a drain for the right handend of the main valve stem passageway which is connected with the pilotvalve stem passageway through passageways 418, 420 and 422. However, inthe structure disclosed in Fig. a. w s in linic 41 54 s P ided betweenthe detent chamber 374 and the pilot valve stem passageway for drainingthe right hand end of the main valve stem passageway. The left end ofthe feed valve stem passageway is connected to the drain by passageways421 and 423.

In order to operate the pilot valves which are normally retained in theneutral position by means of a compression spring 424 disposedtherebetween, solenoids 426 and 428 are mounted on opposite ends of thecontrol valve structure. A lever 430 is pivotally mounted on the endplate 348 and is operable by the plunger 432 when the solenoid 426 isenergized to shift the pilot valve stem 344. A similar lever 434 ispivotally mounted on the end plate 354) and is operable by the plunger436 for actuating the pilot valve stem 346.

The cycle of the sliding head frame work casting is initiated byenergizing the solenoid 426 so that the pilot valve stem 344 is shiftedto the position shown in Fig. 9. With the pilot valve stem 344 in thisposition, the passageway 392 is unblocked while the drain passageway41!) is closed. Thus, the fluid under pressure is permitted to flowthrough the passageway 392 and a restricted orifice member 436 disposedtherein which serves to reduce the flow rate and prevent too rapidshifting of the main valve stem as explained below. During the time thepilot valve stem is shifted, fluid between the pilot valves is forcedthrough a restricted orifice member 438 into the drain line 412, whichrestricted orifice member serves to meter the fluid and prevent fluidfrom the right end of the main valve stem passageway from forcing thepilot valve stem 344 back out. The fluid passing from the passageway 392flows through the passageways 4422, 404 and 406 and into the left end ofthe main valve stem passageway 334 to shift the main valve stem towardthe right without undue force. The solenoid 426 may then bede-energized, allowing the spring 424 to return the pilot valve stem 334to its neutral position without causing any change in the position ofthe main valve stem.

With the main valve stem in the position shown in Fig. 9, the fluidunder pressure from the rapid traverse pump passes across suitable flatsprovided in the spool portion 378 of the main valve stem and through apassageway 440 to the feed valve stem passageway 336. Then the fluidpasses out through the passageway 362 into the conduit means 364 and tothe hydraulic cylinder 192 for causing rapid advance or traverse of thehead frame. Fluid from the rear end of the hydraulic cylinder 102 flowsthrough the conduit means 368 and into the passageway 366, a transversepassageway 442 formed in the main valve stem, the centrally locatedpassageway 382 in the main valve stem and thence out through the reliefvalve 384. It should be noted that with the main valve stem in the rapidadvance position, fluid under pressure is still available in the rightend of the feed valve stem passageway 336 for holding the feed valvestem against the compression spring 396 since the main valve stem isprovided with an L shaped passageway 444 located to communicate with thepassageway 393. The feed valve stem is provided with flats 462 to permitcharging of the feed pump during rapid approach.

At the end of the rapid advance movement of the sliding head frame, themain valve stem 344 is shifted to the position shown in Fig. 10. Inorder to accomplish this shifting of the main control valve stem, ashaft 450 is journalled in the valve body as shown in Fig. 6, whichshaft is provided with a control finger 452 extending into a suitableslot in the main valve stem. A cam member 454 is secured to the shaft459 for engagement with a fixed control dog which will be describedbelow. The main valve stem is held in this position by the ball detent372 which enters a groove 456. In this position, the main control valvestem blocks the passageway 440 so that a major portion of the fluidbeing circulated by the rapid traverse pump is returned to the reservoirthrough the spring-operated orifice or circulating valve 384 and anotherportion of the fluid passes through the passage 390 to the outlet 356from where it is directed to the charging or pre-loading pump 360 andthe feed pump 112 and finally into the hydraulic cylinder 102. It shouldbe noted that when the main control valve stem is in the position shownin Fig. 10, the left hand end of the main valve stem passageway 334 isconnected with the drain and the right hand end of the feed valve stempassageway 336 is also connected with the drain through passageways 398and 400 and an L shaped passageway 458 formed in the main valve stem andconnecting the passageway 398 and the left hand end of the main valvestem passageway. Thus, the pressure in the right hand end of the feedvalve stem passageway is relieved so that the spring 396 shifts the feedvalve stem toward the right to the position shown in Fig. 10. With thefeed valve stem in this position, fluid under pressure from the rapidtraverse pump passes through the passageways 390 and 394 and to the feedvalve stem passageway 336 at a position in alignment with a reduceddiameter or spool portion 460 of the feed valve stem. The pressure ofthe fluid in this portion of the feed valve stem passageway isdetermined by the setting of the circulating valve or spring-operatedorifice 384, and it should be noted that the return line 368 from thehydraulic cylinder is also connected with this portion of the feed valvestem passageway so that the cylinder 102 is operated against a backpressure determined by the setting of the circulating valve 384. Thefluid returning through the line 368 is recirculated through the feedvalve stem passageway and to the feed pump so that a substantiallyclosed feeding fluid circuit of the general type disclosed in my PatentNo. 2,388,716, dated November 13, 1945, is provided. The above mentionedrestricted orifice or passage member 436 does permit sufficient fluid topass into the feeding fluid circuit to compensate for the fact that thevolume of fluid in the end of the cylinder in which the piston rod islocated is insuflicient to fill the opposite end of the cylinder. Withthis arrangement, positive and accurate control of the relative movementbetween the piston and the hydraulic cylinder is obtained during feedingmovement of the main head frame.

At the end of the feeding movement of the sliding head frame, thesolenoid 428 is energized in the manner described below so that thepilot valve 346 is shifted to the position shown in Fig. 11. With thepilot valve 346 in this position, fluid flows through the passageways418, 420 and 422 and into the right hand end of the main control valvestem passageway 334 to shift the main control valve stem to the positionshown in Fig. 11. At any time after the main control valve stem has beenshifted to the left, the pilot valve 346 may be permitted to return toits normal position by-de-energizing the solenoid 428 without causing achange in the position of the main control valve. With the main controlvalve stem in the position shown in Fig. 11, it is seen that fluid underpressure from the rapid traverse pump will enter the passageway 352 andcross suitable flats formed in the spool portion 378 of the main valvestem and then pass through the passageway 366 and to the rear end of thehydraulic cylinder 102 through the line 368. At the same time, fluidunder pressure is restored to the right hand end of the feed valve stempassageway 336 so that the feed valve stem is shifted toward the leftagainst the action of the spring 396. With the main and feed valve stemsin the positions shown in Fig. 11, the forward end of the hydrauliccylinder 102 is connected with the drain through the lines 358 and 364which return the fluid to the feed valve stem passageway 336. The feedvalve stem passageway is, in turn, connected to a portion of the mainvalve stem passageway which is open to the drain by the passageway 440.At the end of the return movement of the sliding main head frame, themain control valve stem is again shifted to the neutral position bymeans of a cam 464 which is mounted on the shaft 450 and which engages afixed control dog described below.

A stationary control bar 692 which is shown in Figs. 1 and 2a isprovided for the sliding head unit and is mounted to the'base 42 by anysuitable means. The bar 692 serves 'as a support for a plurality ofcontrol dogs and limit switches. More specifically, a control dog 694 isprovided for actuating the above described cam 454 of the control valvestructure for shifting the main control valve stem to the feed positionand a switch device 696, which is operated by a cam 698 on the slidinghead, is provided for energizing the solenoid 428, Fig. 3, whichoperates the pilot valve stem 346 in a manner so that the main valvestem is shifted to the reverse position. In addition, a safety device inthe form of a dog 700 is provided for engaging the cam 454 and shiftingthe main valve stem to a neutralposition in the event of a failure ofthe operation of the switch 696 or the electrical control circuit.Still, another dog 702 is mounted on the bar for engaging the cam 464 toshift the main valve stem to the neutral position at the end of thereverse stroke. A limit switch 704 which is operated by a cam 706 on thesliding head is also provided for opening the electric circuit todeenergize the reverse solenoid 428 when the sliding head reaches itshome position.

The control valve body 332 is mounted against a machined surface 482 onthe front side of the head frame structure 44, Fig. 13. The controlvalve 330 is tightly secured against the surface 482 by means of screwswhich are passed through apertures 486 in the head frame. As shown bestin Fig. 13, the head frame 44 is formed with a passageway 488 which islocated to register with the passageway 362 of the control valvestructure. The passageway 488 communicates with a vertically extendingpassageway 490 which intersects a transversely extending passageway 492,Fig. 14, having its outer end closed by plug 494 and having its innerend connected with a downwardly extending passageway 496, Fig. 12. Thepassageway 496 is connected to the forward end of the hydraulic cylinder102 through a suitable passage 498 formed in the body of the hydrauliccylinder, which body is secured against the bottom of the head framestructure by any suitable means, not shown. The head frame 44 isprovided with a transversely extending passage 500, Fig. 13, whichregisters with the passageway 366 in the control valve body 332 andwhich also communicates with a downwardly extending passage 502. Thepassage 502 is connected with the rear end of the hydraulic cylinder 102through a suitable passage 504 formed in the cylinder body, Fig. 12.

The head frame structure is provided with a passageway 506 which opensat the surface 482 and communicates with the passageway 356 of thecontrol valve body 332. The fluid flowing into the passageway 506 isconducted by suitable passageway or conduit means, not shown, to theinlet of a charging or pre-loading pump section 360 of the pumpstructure 110, Figs. 1 and 12.

Another passageway 536 in the machined surface 482 of the sliding headframe 44 connects the drain passageway 370 of the control valve 330 withthe reservoir.

Statement of operation Assuming the sliding head frame structure 44 tobe in home or withdrawn position, the operator initiates operation ofthe machine by first closing a switch, not shown, to effect energizationof the motor or prime mover 52 of the head frame structure or unit 40.As the motor begins, the traverse pump and feed pump 112 begin thecirculation of the hydraulic actuating fluid. At this time, the controlvalve structure 330 is in neutral position, Fig. 8, so that the fluiddelivered by the pumps is merely idly circulated.

The operator then actuates the start button of switch, not shown, tocause the energization of the forward solenoid 426, Fig. 3. The solenoid426 functions to shift the control valve structure 330 to the rapidadvance position, Fig. 9, in the manner fully set forth above. Thus,fluid is directed from the rapid traverse and feed pumps through thecontrol valve structure and to the hydraulic cylinder 182 to eflectrapid advance or approach movement of the sliding head. As the headstructure moves away from home position, the solenoid 4-26 isde-energized. As the head reaches its feed position, its associatedcontrol dog causes the mechanical shifting of the main valve stem 340into the feed position wherein fluid from the rapid traverse pump is cutoil? from the hydaulic cylinder and the cylinder is actuated at a slowerrate by fluid from the feed pump. At the end of the feeding stroke, thelimit switch 696, Fig. 2a, is actuated to energize the reverse solenoid42.8 which causes the main valve stem to shift to the reverse position.Fluid is now circulated from the rapid traverse pump to the hydrauliccylinder to effect rapid reverse movement. As the head frame 44 returnsto the home position, the solenoid 428 is de-energized. Immediatelyafter the de-energization of the solenoid 428 and as the head framesreach home position, the control dog 702 functions to shift the mainvalve stem of the control valve structure to neutral position.

While the preferred embodiment of the present invention has been shownand described herein, many structural details may be changed withoutdeparting from the spirit and scope of the appended claims.

The invention is claimed as follows:

1. In a fluid control system for a self-contained machine tool unit orthe like, a control valve structure comprising a main body, said bodyhaving a first passageway adapted to be interconnected with an outlet ofa rapid traverse pump, a second passageway adapted to be interconnectedwith a fluid motor, a third passageway adapted to be interconnected withan inlet of a feed pump, and a fourth passageway adapted to beinterconnected with said fluid motor, a main valve stem shiftable withinsaid valve body for selectively directing fluid from said firstpassageway to said other passageways, a second valve stem shiftablewithin said body in response to shifting of said main valve stem forcontrolling the flow of fluid into said third passageway, and pilotvalve stem means shiftable within said body for causing shifting of saidmain valve stem.

2. In a fluid control system for a self-contained machine tool unit orthe like, a control valve structure comprising Valve body means, saidbody having a first passageway adapted to be interconnected with anoutlet of arapid traverse pump, a second passageway adapted to beinterconnected with a fluid motor, a third passageway adapted to beinterconnected wtih an inlet of a feed pump, a fourth passageway adaptedto be interconnected with the fluid motor and a drain passageway, a mainvalve stem shiftable within said body means for selectively directingfluid from said first passageway to said other passageways, a secondvalve stem shiftable within said body means in response to the shiftingof said main valve stem for controlling the flow of fluid into saidthird passageway, a pair of pilot valve stems shiftable within said bodymeans for selectively causing shifting of said main valve stem inopposite directions, and electrical means for actuating said pilot valvestems.

3. A control valve for a fluid actuating system comprising a main bodyhaving a first passageway adapted to be interconnected with fluidpressure generating means, a second passageway adapted to beinterconnected with a fluid motor, a third passageway adapted to beinterconnected with the fluid motor, a fourth passageway adapted to beinterconnected with feeding fluid pressure generating means, and a drainpassageway, a first member disposed within said body means forcontrolling the flow of fluid through said passageways and shiftablefrom a neutral position to rapid advance, feed and rapid returnpositions, at second member disposed within said body means andshiftable to block said third passageway when said first member is insaid feed position, said body having conduit means therein extendingbetween said first passageway and opposed portions of said firstmentioned member, a pair of pilot valves slidably disposed within saidbody for controlling the flow of fluid through said conduit means,electrical means for selectively actuating said pilot valves to directfluid through said conduit means to one or" said opposed portions ofsaid first mentioned member to shift said first mentioned member to therapid advance position and to direct fluid through said conduit means tothe other of said opposed portions to shift said first mentioned memberto said rapid return position, and cam means operably connected withsaid first mentioned member for shifting said first mentioned memberfrom the rap-id advance position to the feed position and from the rapidreturn position to the neutral position.

4. A self-contained machine tool unit comprising, in combination, abase, a head assembly movably mounted on said base for translationthereon, a fluid motor interconnected with said head assembly fortranslating the latter on said base, a rapid traverse pump, a feed pump,a control valve comprising a main body; said body having a firstpassageway interconnected with the outlet of said rapid traverse pump, asecond passageway interconneoted with one side of said fluid motor, athird passageway interconnected with the inlet of said feed pump, and afourth passageway interconnected with the other side of said motor;means for interconnecting the outlet of said feed pump with said motor,a main valve stem shiftable within said valve body for selectivelydirecting fluid from said first passageway to said other passageways, asecond valve stem shiftable within said body in response to shifting ofsaid main valve stem for controlling the flow of fluid into said thirdpassageway, and pilot valve stem means shiftable within said body forcausing shifting of said main valve stem.

5. A self-contained machine tool unit comprising, in combination, abase, a head assembly movably mounted on said base for translationtherealong, a fluid motor connected to said head assembly fortranslating the latter on said base and having two fluid connectionsthereto which determine in accordance with the supply to the respectiveconnections of fluid under pressure the direction of translation of saidhead assembly on said base, a rapid traverse pump, a feed pump, acontrol valve structure comprising a valve body means; said body meanshaving a first passageway interconnected with the outlet of said rapidtraverse pump, a second passageway interconnected with said fluid motorthrough one of said fluid connections thereof, a third passagewayinterconnected with the inlet of said feed pump, a fourth passagewayinterconnected with the other of said fluid connections to said fluidmotor, and a drain passageway; a main valve stem shiftable within saidbody means for selectively directing fluid from said first passageway tosaid other passageways, a second valve stem shiftahle within said bodymeans in response to the shifting of said main valve stem forcontrolling the flow of fluid into said third passageway, means forinterconnecting the outlet of said feed pump to said one fluidconnection to said fluid motor, a pair of pilot valve stems shiftablewithin said body means for selectively causing shifting of said mainvalve stem in opposite directions, and electrical means for actuatingsaid pilot valve stems.

6. A control valve for a machine tool fluid actuating system,comprising, in combination; a main body having a first passagewayadapted to be interconnected with fluid pressure generating means, asecond passageway adapted to be interconnected with a fluid motor, athird passageway adapted to be interconnected with the fluid motor, afourth passageway adapted to be interconnected with feeding fluidpressure generating means, and a drain passageway; a first memberdisposed within said body means for controlling the flow of fluidthrough said passageways and being shiftable from a neutral position torapid adnearest vance, feed, and rapid return positions; a second memberdisposed within said body means and shiftable to block said thirdpassageway when said first member is in said feed position, said bodymeans defining passage means therein extending between said firstpassageway and opposed portions of said first member, pilot -valve meanshoused within said body controlling the flow of fluid through saidpassages to said opposed portions of said first member to effectshifting of said first member in opposite directions, electrical meanscoacting with said pilot valve means to operate the latter to directfluid to one of said opposed portions of said first member to shift saidfirst member to the rapid advance position thereof and alternatively todirect fluid to the other of said opposed portions of said first memberto shift said first member to said rapid return position thereof, andmechanical control means connected with said first member for shiftingthe latter from the rapid advance position thereof to the feed positionthereof and for shifting the first member from the rapid return positionthereof to the neutral position thereof.

7. For use on a machine tool having a head frame defining a plurality ofpassages opening therethrough, a fluid control system comprising, incombination, a body adapted to be demountably secured to the machinetool head frame in covering relation to the passages therein; said bodyhaving a first passageway opening outwardly therethrough to beinterconnected with the outlet of a rapid traverse pump, a secondpassageway opening outwardly therethrough to be interconnected with afluid motor, a third passageway opening outwardly therethrough to beinterconected with the inlet of a feed pump, a fourth passageway openingoutwardly therethrough to be interconnected with the fluid motor, and afifth passageway opening outwardly therethrough to be connected todrain; said passageways opening outwardly through said body in positionsfor registering with corresponding passages in the machine tool headframe, a main valve stem shiftable within said body for selectivelydirecting fluid from said first passageway to said other passageways, asecond valve stem shiftable within said body in response to shifting ofsaid main valve stem for controlling the flow of fluid into said thirdpassageway, a pressure control valve carried within said main valve stemto connect said first passageway with said fifth passage way inaccordance with the position of said main valve stem, and pilot valvemeans shiftable within said body for causing shifting of said main valvestem.

8. In a fluid control system for a machine tool, control valve structurecomprising, in combination; a valve body having a first passagewayadapted to be interconnected with an outlet of a rapid traverse pump, asecond passageway adapted to be interconnected with a fluid motor, athird passageway adapted to be interconnected with the inlet of a feedpump, a fourth passageway adapted to be interconnected with the fluidmotor, and a drain passageway; a main valve stem shiftable within saidbody for selectively directing fluid from said first passageway to saidother passageways, a pressure control valve carried by said main valvestem to be interconnected between said first passageway and said drainpassageway when said main valve stem is shifted to a position forconnecting said first passageway to said drain passageway, a secondvalve stem shiftable within said body in response to the shifting ofsaid main valve stem for controlling the flow of fluid into said thirdpassageway, pilot valve means housed within said valve body andinterconnected through passages in said body with said main valve stemto effect shifting of said main valve stem from one position to another,and restricted passage means connected in series with said pilot valvemeans for metering the rate of fluid flow therethrough to effectshifting of said main valve stem.

References Qitetl in the file of this patent UNITED STATES PATENTS1,943,061 Douglas Ian. 9, 1934 1,970,181 Monroe Aug. 14, 1934 1,972,462Schafer Sept. 4, 1934 1,972,560 Heller Sept. 4, 1934 2,276,358 VickersMar. 17, 1942 2,388,716 Svenson Nov. 13, 1945 2,559,125 Lee July 3, 19512,594,664 Livers et a1 Apr. 29, 1952

